Of critical concern to the National HIV Vaccine Program is the design of HIV immunogens which can elicit broadly neutralizing antibodies (group-specific) rather than neutralizing antibodies of narrow specificity (type-specific). Current evidence indicates that group-specific antibodies recognize conformational epitopes which are dependent in an unknown manner on glycosylation of gpl20. This study is designed to probe the effect of N-glycosylation of the HIV env-proteins on these conformational epitopes and determine whether there are critical glycosyl residues involved in the maintenance of native conformation of these group-specific epitopes. This study will analyze the effects of inhibition at various steps of N-glycosylation processing (i.e.-global effect) and the HIV glycosylation patterns dependent on the producer cell (i.e.-site-specific effect) as a function of neutralization by conformation dependent neutralizing monoclonal antibodies. Differential peptide mapping and enzymatic analysis of glycosyl units will be used to target specific glycosylation sites (Asn-X-Ser/Thr) for subsequent microsequence analysis of site-specific carbohydrate structure.